Work has begun on refurbishing the Moyle interconnector, a 500MW HVDC link owned and operated by Mutual Energy which links Northern Ireland and Scotland.

Siemens Gas and Power won the project to refurbish the interconnector, whose control and protection system is almost 20 years old. The project is scheduled to be completed in September 2022. Mutual Energy said the refurbishment would not require long periods with the interconnector out of service, because  “Moyle has two ‘poles’ and the outages will be taken on a pole-by-pole basis between spring and autumn 2022. There will only be a few days where a complete outage is required.”

Siemens said that by introducing an overload capability, the upgraded Moyle Interconnector will have greater operational flexibility, and the upgrade improves the dynamic performance of the interconnector, enabling Mutual Energy to offer enhanced ancillary services. Mutual Energy explained, “The capability and reliability of the interconnector to provide flexible and adjustable high and low frequency response will be enhanced across its operating range.” It also said, “The upgrade will allow the interconnector to deliver low load capability and ancillary services seamlessly through the zero-load point.”

The interconnector has been constrained on utilising its full 500MW capacity but Mutual Energy said that would not be affected by the upgrade: “The constraint on reaching the interconnector’s 500MW capacity is due to restrictions on the connected grids, primarily the Scottish system. The upgrade will not change these restrictions but will allow the interconnector to better use additional system capacity when it becomes available, and as the Northern Ireland and Scottish grids evolve.”